Published onJune 17, 2026Database Sharding with Spring Boot and PostgreSQL: Routing, Resharding, and Operational BoundariesDatabase-ShardingSpring-BootPostgreSQLJPAData-RoutingReshardingDistributed-SystemsDecide when PostgreSQL sharding is justified, choose a stable shard key, route Spring Boot transactions safely, preserve uniqueness and idempotency, plan cross-shard queries, and migrate data without losing writes.